There is likely to be a shortage of organic eggs, milk and poultry in a few months, producers have warned.

Organic wheat - a vital mainstay of the organic farm animal's diet - is in chronically short supply this year, with prices already up 50% compared with last year. Expensive feed means expensive dairy produce, which could lead to shortages in supermarkets, producers said.

To avoid bare shelves they say prices will have to rise until demand is balanced against supply - at a time when retailers are keen to increase shelf space for organic products.

"I don't think there'll be empty shelves but it will restrict the growth in production of livestock products," said Patrick Holden, director of the Soil Association. "Consumers may be disappointed, but it's better to maintain the quality of products than compromise, even if the price goes up. It won't damage demand for organic products in the long run." Demand for organic produce is still rocketing, with milk alone achieving 30.5% volume growth last year, according to Omsco. But organic wheat production has not kept up. A recent change to the law also means organic animals have to be fed up to 95% organic feed, boosting wheat demand.

"Grain traders are going to start running out in two to three months," said Richard Jacobs at organic certification body, Organic Farmers and Growers. "Everyone in Europe had a poor harvest. Livestock will lose organic status if feed runs out because there's no support for a derogation allowing more non-organic feed into their diets."

The shortage could also affect red meat but the main threat was to egg, milk and poultry production, Jacobs said. Sales of organic eggs have already fallen 3.7% in the year to 3 December [TNS] as prices rose 12%. Half a dozen medium organic eggs now cost about £1.45.